关键词: 嵌段共聚物, 临界胶团温度, 临界胶团浓度, 自组装行为, 调控, 应用

Abstract:

Water-soluble poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers are high-molecular-weight nonionic surfactants, which exhibit the richest structural polymorphism in selective solvents. One of the most interesting features of the triblock copolymers is their self-association in aqueous solutions and their rich phase behavior. The microstructure resulting from the self-assembly of the triblock copolymer can vary from normal micelles in solution, through all types of normal and reverse lyotropic liquid crystals (normal micellar cubic, normal hexagonal, normal bicontinuous cubic, lamellar, reverse bicontinuous cubic, reverse hexagonal, reverse micellar cubic), to reverse micelles, as the relative volume fraction of the apolar components increases over that of the polar components. The self-assembly properties of PEO-PPO-PEO triblock copolymer in aqueous solutions are reviewed. Experimental techniques such as scattering techniques, spectroscopy techniques, viscometer, surface tension, ultrasonic velocimetry, differential scanning calorimetry, size exclusion chromatography and transmission electron microscopy for studying self-assembly behaviors of PEO-PPO-PEO triblock copolymers are introduced. Effects of structure of the block copolymer, molecular mass, temperature, concentration and additives such as inorganic salts, alcohols, oils, surfactants, ionic liquids and different block copolymers on self-assembly behaviors are introduced. A general overview of thermodynamic theories, molecular simulations and computer simulations of block copolymer micellar systems is also presented. Current applications of block copolymer as synthesis of mesoporous materials, controlled delivery of drug agents, separation of biomacromolecules and modification are also discussed.

Key words: 嵌段共聚物, 临界胶团温度, 临界胶团浓度, 自组装行为, 调控, 应用